Metallic vapor lamp



Jan. 24, 1928. 1,656,898

' R. L. M. BELLEAUD ET AL METALLI C VAPOR LAMP Filed Jan. 30. 1924 Patented Jan. 24, 1928.

UNITED STATES PATENT OFFICE.

BEBE LOUIS MAXINE IBELELEAUD AND JEAN BARBOLLIER, OF GO'IJ'RBEVOIE, FRANCE.

METALLIC vnroa LAMP.

Application filed January 80, 1924, Serial No. 689,407, and in France February 14, 1923.

The germicidal power of quartz mer- Lamps embodying our invention are cury vapor lamps is well known. It is shown, by way of example, on the accomalso well known that the maximum abiotic panying drawing, in which power, when such lamps are employed, for Fig. 1 is a longitudinal section of an iminstance, to sterilize water, is obtained when proved mercury vapor lamp, and

they are immersed in the body or" the liquid, Fig. 2 a longitudinal section of a modithe illuminating tube being then in direct fied construction. contact with the water undergoing treat- The mercury vapor lamp shown in Fig. 1 ment. comprises an elbowed tube 1, of quartz. 2 Always, however, when the lamp consists and 3 are the electric terminals. 4 is the simply of a tube, it is not long, on the lamp mercury at the anode and 5 is the mercury being in operation, before an accumulation at the cathode. 6 is a mass being a poor of mercury is observed at the negative pole. conductor of heat consisting, for example, of Such accumulation results from electric an agglomerate of cement and fused sand transference of the mercury by the arc and and placed around a portion of the quartz a distillation of the mercury due to the diftube 1 so as to partially surround the 'ference of temperature between the anode negative electrode.

and the cathode. resents the are.

*Our present invention provides a mercury of short wave length is in direct contact by a rocking of the tube, the negative pole with the liquid in which the lamp is im-' being raised and the positive pole depressed, mersed, and in which lamp a state of merin which case some of the mercury 5 flows curial equilibrium is obtained between the toward the mercury 4. The level 7 of the The broken line 8 'rep- The lamp is operated when immersed, for Y lamp the tube of which. emitting radiations example in water. The are may be started anode and thecathode, so that the lamp can mercury 5 assumes a certain position within be usedwithout interruption for long pethe heat insulating mass 6 and may even be riods of time. below such mass. Now, it will be observed Our invention consists in screening, to a that at the beginning of the operation, the suflicient extent the negative electrode of the level of the positive mercury 4 tends to delamp, which is the colder electrode, from scend whilst the level of the negative merthe action of the medium in which the lamp cury 5 on the other hand tends to rise be is immerserd. This end we obtain by parcause of the transfer of the mercury until, tially or completely surrounding the negaat a given instant the level 7 of the negative tive electrode with a jacket being a poor conmercury 5 assumes a position wherein this ductor of heat, or composed of one or'more mercury, being sufficiently protected by the substances being poor conductors of heat. heat insulating mass 6 against the cooling It is conceivable that under these conditions, action of the surrounding liquid, acquires a when the lamp is immersed in a liquid, temperature ca able of ensuring a state of for-example water to besterilized, the lamp mercurial equilibrium with the positive pole; is completely in contact with the liquid and The level 7 of the negative mercury 5 asis subjected to the cooling action thereof, sumes different positions, in accordance with except at the place where the negative electhe. characteristics of the tube and of the trode is protected by the heat insulating electric supply current, and such positions, jacket. The are therefore is surrounded at corresponding to the state of mercurial equithe cathode by a sheath which rotects it librium, are assumed automatically. from the coohng action of the qu d and Obviously, without any departure from permits the cathode region to attain such the spirit of the invention, the heat insulaa temperature that mercurial equilibrium tion embracing all or part of the negative between the anode and the cathode is obelectrode can be provided invarious ways 5o tained. i For example, 'accordin to Fig. 2, it may The state of equilibrium under these conconsist of a quartz enve ope 10 fused to the -ditions. is automatically reached, the level illuminating tube 1,.the annular space he of the mercury atthe negative pole of itself tween the illuminating tube 1 and such en'- assuming the height favourable as regards velope 10 being exhausted through a connecthe characteristics of the tube and of the tion, subsequently sealed asa tip 11,the same electric supply current. as on bulbs of electric incandescent lamps.

'for retarding The invention obviously is applicableto all metallic vapor lamps, whatevenbe the nature of the metallic vapor, whether it be produced by mercury, by an amalgam or otherwise, and whatever he the nature of the fluid (either liquid or gas) in which the lamp is immersed.

We claim- 1. In a metallic vapor tube for submersion in a liquid, an anode, a cathode, and means for retarding the transmission of heat from the transmission of heat from said cathode to the liquid in comparison in a liquid, an anode, a cathode, and means 7 for retarding the transmission of heat from said cathode to the liquid in comparison with the transmission of heat from said anode to the Pquid, comprising an evacuated jacket around-said cathode for thermally insulating said cathode only.

In testimony tures.

Rani. Louis mxma muawn. mu snowman.

whereof we afiix our signa- 

